The invention relates to a cooling system of an electronic computer and, more particularly, to an electronic computer in which an operating speed of a semiconductor device is raised to thereby improve an operating speed of a computer system and also relates to a cooling system of such an electronic computer.
A conventional electronic apparatus has a construction in which one or more fans are provided to cool a number of heat generating sources such as package, disk, power source, and the like which exist in a casing. A cooling air is blown by the fans and enters the casing through holes and flows in the casing along the package, disk, and power source and flows to the outside of the casing by the fans. In such a construction, an inflow temperature of the cooling air is equal to a room temperature. There is a case where, for example, a temperature of the main portion of the package rises to about 50.degree. to 100.degree. C. even when it is sufficiently cooled. As a method of improving the cooling of the package as mentioned above, there is an example in which channels are formed by surrounding the package by partition plates and fans are arranged before and after the channel as disclosed in JP-B-60-11830 (JP-A-53-145054). The publication also shows an example of coupling via heat pipe a cooling air inlet side with a heat source of very large heat capacity among various heat sources.
In "IEEE Transaction on Electron Devices", Vol. 36, No. 8 (1989), page 1404, a cooling system in which a board on which CMOS devices are mounted is dipped in liquid nitrogen is disclosed. As disclosed in JP-A-1-270296, there is a cooling system in which an inflow air is previously cooled by a refrigerating cycle.
Among the above conventional techniques, in the case of the cooling system by the fans disclosed in JP-B-60-11830, to increase the cooling capacity in order to further reduce the temperature of semiconductor device, a flow rate of the air must be increased by increasing the number of fans, by increasing the size of fans, or the like. In such a case, there is a problem of an increase in fan noises. On the other hand, there is also a problem such that when the size of radiating fans is increased in order to enhance the cooling capability, a high installing density is not obtained. Further, the temperature of semiconductor device cannot be held to a temperature less than the external air temperature and no consideration is given to the realization of a high operating speed of the device due to the realization of a low temperature.
On the other hand, according to the example in which the board on which the semiconductor device is mounted is dipped into liquid nitrogen, there are problems such that the size of refrigerator is large and another casing different from the casing enclosing the semiconductor device is needed, so that a large occupied area is necessary. According to the system disclosed in JP-A-1-270296, since all of the devices are uniformly cooled, no consideration is given to the realization of a high operating speed of a special device and the dehumidification.